Esterification of ε-N-carbobenzoxy- L -lysine with boron trifluoride – alcohol

The esterification of ε-N-carbobenzoxy-L-lysine with various boron trifluoride – alcohol mixtures at 80 °C leads to some deprotection, which increases as the chain length of the alcohol increases. A convenient synthesis of ε-N-carbobenzoxy-L-lysine methyl ester in 58% yield from ε-N-carbobenzoxy-L-lysine and boron trifluoride – methanol has been developed.